Spring loaded whip arrester for boom suspension cables



K. SCHNEIDER March 7, 1967 SPRING LOADED WHIP ARRESTER FOR BOOM SUSPENSION CABLES Filed Sept. 17, 1965 INVENTORI KARL SCHNEIDER AiffomvEY United States Patent SPRING LOADED WHIP ARRESTER FOR BOOM SUSPENSION CABLES Karl Schneider, Greenfield, Wis., assignor to Harnlsehfeger Corporation, Milwaukee, Wis., a corporation of Wisconsin Filed Sept. 17, 1965, Ser. No. 488,025 3 Claims. (Cl. 214-135) The present invention relates generally to power shovels having an upwardly extending boom held in place by suspension cables. A dipper handle having a dipper attached to it is mounted on the boom. The invention relates more particularly to means for arresting the side sway or whip of these cables.

In shovels of this type, the boom suspension cables are subjected to violent whipping action if the-boom is jerked up momentarily and then permitted to drop back on the cables. Stated otherwise, when the dipper is raised and lowered in rapid succession, the cables sometimes sway sideways. As the dipper handle is located closely to the swaying cables, the latter sometimes become entangled with the heel or upper end of the handle, thus causing damage to the cables.

Accordingly, the present invention provides cross connected spring loaded and flexible means for damping the whipping action of boom suspension cables of a power shovel.

A more specific aspect of the present invention contemplates means of the above type having a spring lo-aded clamp for clamping the cables but which permits the cables to turn about their own axis without necessitating corresponding twisting of the clamp itself which could otherwise turn and diminish the amount of clearance between the cable and handle. The arrangement is such that the whip arresting means can remain in the proper location along the inclined cables even though the clamping action may be momentarily relieved when arresting the cable whip.

These and other objects and advantages will appear hereinafter as this disclosure progresses, reference being had to the accompanying drawings, in which:

FIGURE 1 is a perspective view of a power shovel embodying the present invention;

FIGURE 2 is a transverse, cross sectional view through the suspension cables shown in FIGURE 1, but on an enlarged scale; and

FIGURE 3 is a view taken along line 3-3 in FIGURE 2, but with the U bolts removed.

Referring in greater detail to the drawings, the power shovel includes a lower, endless track portion 1 and a rotatable upper support portion 2 to which a boom 3 is pivoted at its lower end at 4, and extends upwardly at an incline. A plurality of boom suspension cables(four in this illustration), 5, 6, 7 and 8 are secured at one of their ends to the rigid A-frame 9 on portion 2, and at their other end to the upper end of the boom. Various numbers of cables may be used, but in the arrangement shown, these four cables are arranged in parallelism and in the form of a rectangle when viewed in transverse cross section, as shown in FIGURE 2. Thus the boom is held at an inclined position but can move upwardly about its pivot point during operation.

A dipper 10 is attached to the lower end of the dipper handle 11 which can be moved generally along its axis, that is generally up and down, in the saddle block 12 which is pivoted at 13 to the boom. The handle can also be swung about the pivot 13 in the known manner to position and load the dipper, by means of the power driven cables 15 trained over the sheave 16 at the upper end of the boom, all in the conventional manner.

3,307,721 Patented Mar. 7, 1967 ICC It will be noted that a certain amount of clearance is provided between the suspension cables and the upper ends of the dipper handles between which the cables pass. As the dipper is crowded into the material, the boom may be at times jerked upward in case the operator should apply an inordinate amount of crowding force, causing the suspension cables to sag and sway in .a violent whipping ac-tion sometimes catching on the upper end of the handle and becoming snagged and damaged. It is to this problem that the present invention is directed.

In accordance with the present invention, means are provided for damping and controlling this whipping :action, but at the same time provide flexibility between the suspension cables without reducing the clearance between the cables and bucket handle. The cables are permitted to turn about their own axis by means of resiliently loaded clamps now to be described.

Sets S of cross cables 20 and 21 are positioned diagonally between the four suspension cables and at spaced locations along their length so that cross cable 20 is connected between the diagonally opposite cables 4 and -7, and cross cable 21 connects between the diagonally opposite cables 5 and 6. Cables 20 and 21 are secured together at their point of juncture by ring 22. The cross cables are connected through clevises 31 to the suspension cables by means of spring loaded cable clamps 25, now to be described.

Each of these four clamps 25 includes a pair of U-bolts 26 which embrace suspension cables 4, 5, 6 and 7 and pass through a plate 27 and are held captive therein by nuts 28. A spring base 29 has a rod bolt 30 extending therefrom and passing through plate 27, and this rod bolt has a rope clevis 31 engaged on its end. A spring 32 is mounted around the rod bolt 30 and acts against the plate 27 and base 29 to urge the latter into tight, but yieldable, clamping engagement with the suspension cables.

In operation, when the suspension cables whip the spring 32 can permit the base 29 to yield when the force thereon reaches a predetermined amount thus permitting the suspension cable to turn about its own axis and relative to the clamp or without the clamp following this turning action and thus diminish the existing clearance with the dipper handle. This insures that the maximum distance between the suspension cables is maintained while permitting the minimum distance between suspension cables to vary. Thus a certain amount of controlled flexibility is permitted between the cables, the cable whip is dampened and the cables are prevented from entanglement with the dipper handle.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. A power shovel having a support portion, a boom pivoted at its lower end to said portion and extending upwardly at an incline therefrom, suspension cables extending between said support portion and said boom for preventing downward movement of said boom beyond a predetermined position, a dipper handle shiftably mounted on said boom for movement relative thereto, a cross cable connected between said suspension cables and having means for being yieldingly clamped thereto, and spring loaded clamping means for yieldingly clamping said cross cable to said suspension cables, said clamping means including a U-clamp and a base which cooperates therewith and is resiilently urged thereagainst for holding said suspension cable therebet-ween.

2. A power shovel having an upper, rotatable support portion, a boom pivoted at its lower end to said portion and extending upwardly at an incline therefrom, a plurality of parallel suspension cables extending between said support portion and said boom for preventing downward movement of said boom beyond a predetermined position, a dipper handle shiftably mounted on said boom for movement relative thereto, and a cross cable connected transversely between said suspension cables, and spring loaded clamping means for yieldingly clamping saidcross cable to said suspension cables, said clamping means comprisin a U-clamp embracing said suspension cable, a base which cooperates with said U-clamp to clamp said suspension cable therebetween, and a spring which urges said base tightly but yieldingly against said suspension cable.

3. The shovel as defined in claim 2 fiurther characterized in that there are four parallel suspension cables arranged in transverse cross section, and a pair of crosscables are arranged diagonally between said four suspension cables, one cross cable connecting the two diagonally opposite suspension cables.

References Cited by the Examiner UNITED STATES PATENTS 819,576 5/1906 McCabler 294-81 X 2,801,127 7/1957 Koons et a1 294-81 2,947,430 8/1960 Schneider 214136 FOREIGN PATENTS 517,224 1/ 1940 Great Britain.

in rectangular relationship with one another when viewed 15 HUGO O. SCHULZ, Primary Examiner. 

1. A POWER SHOVEL HAVING A SUPPORT PORTION, A BOOM PIVOTED AT ITS LOWER END TO SAID PORTION AND EXTENDING UPWARDLY AT AN INCLINE THEREFROM, SUSPENSION CABLES EXTENDING BETWEEN SAID SUPPORT PORTION AND SAID BOOM FOR PREVENTING DOWNWARD MOVEMENT OF SAID BOOM BEYOND A PREDETERMINED POSITION, A DIPPER HANDLE SHIFTABLY MOUNTED ON SAID BOOM FOR MOVEMENT RELATIVE THERETO, A CROSS CABLE CONNECTED BETWEEN SAID SUSPENSION CABLES AND HAVING MEANS FOR BEING YIELDINGLY CLAMPED THERETO, AND SPRING LOADED CLAMPING MEANS FOR YIELDINGLY CLAMPING SAID CROSS CABLE TO SAID SUSPENSION CABLES, SAID CLAMPING MEANS INCLUDING A U-CLAMP AND A BASE WHICH COOPERATES THEREWITH AND IS RESIILENTLY URGED THEREAGAINST FOR HOLDING SAID SUSPENSION CABLE THEREBETWEEN. 